Hi. I’m a Senior Applied Cryptographer at Aztec Protocol. I also write crypto tasks for CTFZone and teach a cryptography course at NRNU MEPhI. Here I will post about applied cryptography, fuzzing, CTF tasks, peculiar bugs and similar stuff.
Introduction Some time ago Guido Vranken (please check out his blog) stumbled upon the cryptographic library Barretenberg that is being developed by our team at Aztec Protocol. As the creator of probably the most successful differential cryptographic fuzzer there is, he quickly found several bugs that our internal audits had overlooked. One of the more serious ones that he found was a bug in the assembly code intended to perform Montgomery squaring....